argument from analogy

In the wake of the Copernican Revolution, it became common to argue the case for pluralism based on analogy between Earth and the other planets circling the Sun. Since those in favor of pluralism generally assumed that (a) the other worlds of the Solar System were similar to Earth, and (b) God would not have created a lifeless worlds (see teleology), the conclusion followed that all the solar planets supported life. By the middle of the 16th century, analogical reasoning had been extended to other stars which, now considered to be suns in their own right, would have been wasted had they not their own systems of inhabited planets.